No description available.

no / This study presents an investigation of the mutual coupling between two printed elements antenna for a multiple-input-multiple-output (MIMO) antenna performance. It consists of two crescent shaped radiators placed symmetrically, and a neutralization line is applied to improve the mutual coupling. Theoretical and experimental characteristics are presented and compared. The antenna yields an achieved impedance bandwidth of 18.67 % (over 2.04–2.46 GHz) with a reflection coefficient <−10 dB and mutual coupling minimization of <−20 dB in addition to a reasonable and stable radiation pattern and envelope correlation.

Yes / In this work, miniaturized tunable two-antenna MIMO systems composed of printed F-slot shaped is developed to operate in the GPS, PCS, DCS and UMTS bands. The two-element MIMO antenna occupies a volume of 50 × 37.5 ×1.6 mm3, and is printed on an FR4 substrate. Initially, the frequency tunability of the MIMO antennas was verified by lumped capacitors with values between 0.75 to 2.75 pF to achieve a tuning range from 1.55 to 2.07GHz while the low mutual coupling between the radiators was accomplished by adding an I-shaped branch to a cut-away ground plane. The two antennas are then loaded with varactors to simultaneously achieve miniaturization and tunability. Simulation and measurement results demonstrate the successful implementation of a tunable MIMO with coupling reduction mechanism for a portable handheld wireless transceiver. The channel capacity of the proposed antenna is investigated and found to be close to that of an un-correlated system with efficient diversity in which the mutual coupling across the full bandwidth was better than -13dB. Owing to the compact size and ease of manufacture, the proposed antennas can be a promising solution for adaptive MIMO systems in handheld devices. / This work has been performed in the framework of ARTEMOS project under work programme ENIAC JU 2010 and FCT (Fundação para a Ciência e Tecnologia) .The authors would like to thank Datong PLC (Leeds LS18 4EG, West Yorkshire, U.K.), for their financial support of the Knowledge Transfer Partnership (KTP No: 008734).

No / Beamforming is used to achieve diversity gain. It is a technique in diversity to remedy power penalty due to channel fading. The beam-weights for multi-antenna system are evaluated for two different approaches. These weights are then used to weight the signal beams of each transmit antenna branch. Results reveal that by exploiting the transmit channel substructures exposed by the singular vector decomposition algorithm, the capacity of a multi-antenna system can be enhanced.

No abstract / Decision Sciences / M. Sc. (Operations Research)

No description available.

No description available.

No description available.

No description available.

No description available.